1. The document discusses the production of fish meal, which is a concentrated feed obtained by milling and drying fish flesh that is high in protein and minerals. 2. Key steps in the production process include heating fish to coagulate proteins, pressing to separate solids from liquids, drying the solids, and grinding into a powder. 3. Pelagic fish like sardines, mackerel, and anchovies are commonly used as raw materials for fish meal production due to their high protein content and availability.

1. A Seminar on
SUBMITTED TO-
PROF. K. C. DORA
DEPT.OF FPT
SUBMITTED BY-
ASIK IKBAL
M.F.Sc. 1st yr. 2nd sem
DEPT. OF FPT.

2. INTRODUCTION:
Fish undoubtedly is one of the most nutritious food available
for human consumption. Fish flesh on an average contains 15-
20% protein. Judicious and economic utilization of fish should
have a programme of proper disposition of such fish and
fishery waste by processing them into different products
intended for human consumption, animal nutrition or
industrially useful products. The traditional fishery by-products
are fish meal, fish body and liver oils, fish maws etc.

3. FISH MEAL:
• A crude flour obtained after milling and drying fish flesh
• It is a concentrated feed with high quality protein and minerals
like calcium, sodium, potassium, phosphorous
• It contains certain unidentified factors capable of promoting
growth of animals
• Pelagic fishes like sardines, mackerel and anchovies support the
world’s fish meal industry.

4. RAW MATERIALS:
• Any fish/shell fish
• Pelagic small variety of fishes such as anchovies, herring, pilchard, sprat,
sand eel, capelin mackerel, horse mackerel – known as “ industrial fish”
• Fresh raw material provide highest yield and best quality final products
• Chemical preservatives were used for long time storage , but not used in
the present day..
• Principally raw materials are preserved by chilling – mixing with ice and
RSW system.

5. Fish caught
solely for fish
meal (industrial
fish) Fish offals
Fish wastes
from other
processing
operations
THERE ARE THREE TYPES OF RAW MATERIALS

6. PRODUCTION:
• Steps common in commercial production of fish meal:
–Heating or cooking to coagulate protein and release of
water and oil
–Pressing to separate liquid from solids
–Drying
–Grinding to produce a powdered or granular end product.

7. 1. DRY REDUCTION PROCESS:
• Dry rendering or dry reduction is the process employed to process fish
meal from non-oily fish and fish offal.
• The process is ideal for batch operation and hence can be
advantageously employed even when the quality of raw material to be
processed is very small, it can be dried in the sun and pulverized.
• When a sufficiently large quantity is to be processed, the raw material is
first coarse ground and fed into a cooker drier. The cooker drier is a
steam jacketed vessel equipped inside with a power driven stirring
device, usually a paddle type stirrer. The stirrer is rotated continuously,
but slowly throughout the drying process. The cooker drier may be
operated under atmospheric pressure or under partial vacuum.

8. PROCESSING OF PRESS LIQUOR:
• The press liquor enters a centrifuge or desludger where small-suspended
solids are removed from the oil water mixture. This continuous centrifuge is
usually of the conical scroll-type and is often referred to as a decanter
centrifuge in the fish meal industry.
• The solids are returned to the drier to be dried with the press cake, while the
liquid, after appropriate temperature adjustment, is pumped to the oil
separator. The oil separator is another centrifuge, usually of the disc type,
which separates the oil and water. Disc type centrifuges are used because
they are designed for separation of two liquids. They generate the higher
acceleration forces necessary to achieve a good oil water separation.
• Usually the oil is “polished” (i.e. remaining solids and other impurities are
removed) by multiple stages of centrifuging, some of which have hot water
added to help purification of the oil.

9. Contd…
• After suitable polishing the oil is pumped to storage tanks. Hardening and
other additional treatments are usually carried out at the oil user’s facilities.
• The water fraction leaving the oil separator, stick water, is a sticky mixture of
fish solids (5.6%), water (94%) and a small amount of oil (about 0.4%). The
name stick water comes from the fact that the material is quite sticky. The
stick water is fed to an evaporator, typically a double or triple effect system,
where the solids are concentrated to between 30 and 50%. Because stick
water often represents 50% of the original raw fish weight and contains about
20% of the solids in the final meal, recovery of stick water solids is an
economically profitable process.

10. PROCESSING OF SOLIDS:
• The press cake, concentrated stick water, and the solids removed
during centrifuge of the oil are mixed and fed to a drier.
• There are several types of driers used, the choice depends on the
plant conditions. Direct hot air driers and indirect systems using steam
or hot water are popular systems.
• The process is mainly for low fat fish, fish offal, filleting waste etc.
• Traditionally fishes are dried up to a moisture content of 10% and then
pulverized.

11. Advantages
• High yield of oil, even for non
fatty fish
• Suitable for small batch operation
• Simplicity of manipulating
cooking/drying times
• Greater flexibility
• Production of whole meal with
soluble
Disadvantages
• Inferior quality of the oil
• High installation and production
cost
• The slow production

12. Raw fish
Cooker
Press Stick waterPress
liquor
Press cake
Centrifugation
Crude oil
Wet mill
Dryer
Fish meal
Screen
Wet reduction process

13. ADVANTAGES
• 1. Good quality of the oil
• 2. The faster processing
• 3. The lower installation and
operation cost
• 4. Suitable for processing large
quantities of material
• 5. Yield of fish solubles as a
valuable by-product
DISADVANTAGES
• 1. Low water soluble contents of
the meal unless concentrated
stickwater is added
• 2. The lower yield, and
• 3. Rigid operating conditions.

14. MACHINERY:

15. Cooker –
The cooker drier is a steam jacketed vessel equipped inside
with a power driven stirring device, usually a paddle type
stirrer. The stirrer is rotated continuously, but slowly
throughout the drying process. The cooker drier may be
operated under atmospheric pressure or under partial vacuum.
Press –
Usually single or twin screw press. Double screw press is
advantageous as no slippage of materials take place.

16. Centrifuge –
It includes decanter centrifuge, cylindrical, rotor bowl, vertical
disc type centrifuge. The press liquor enters a centrifuge or
desludger where small-suspended solids are removed from the
oil water mixture. The oil separator is another centrifuge,
usually of the disc type, which separates the oil and water. Disc
type centrifuges are used because they are designed for
separation of two liquids.
Multi-effect evaporator –
stick water is passed over a series of heated plates, steam
generated in it is used at subsequent effects at reduced pressure

17. Drier – Two types:
• Direct drier: Direct driers consist of a slowly rotating cylinder, which
conveys the drying meal through it. Air heated by an open flame is blown in
a parallel current mode through the drier. Inlet temperatures as high as 6000
C can be used because evaporation from the wet meal particles cools them
prevent loss of nutrition value. Driers capable of handling 1000 tonnes of
raw material per 24 hour a day are commercially available.
• Indirect drier: It consist of fixed cylindrical drums with internal rotating
scrappers or flights, which continuously stirr the meal as it is being dried.
The flights internally heated by a hot fluid such as steam, supply heat
necessary for drying. There is no contact between the primary heating fluid
(e.g. steam) and the meal. Indirect drier of the disc, coil, or tube types are
used. Air blown through the driers removes the evaporated moisture.

18. • Separator: After drying, the meal is usually passed through a separating
process to remove hooks, cans, plastic bags, and other extraneous
materials from the meal. Vibratory screens, magnetic separators, and other
devices are used to remove unwanted contaminants.
• Hammer mill: Mill particle size as it leaves the drier is quite varied. Since
most markets demand a uniform particle size, the meal is ground. Although
various types of grinders are used, the Hammer mill is most popular.
Swinging hammers grind the meal until it passes through a screen having
openings of the desired maximum particle size.

19. CONTROL OF QUALITY:

20. • Rancidity development:
– Oxidation of oil generate heat and may result fire hazard on storage
– Prevention: Allow oil to oxidize before packing by – spreading out fish meal on
floor before packing, sacks of meal could be kept individually for few weeks to
allow oxidation and generated heat will be dissipitated
– Packing of meal in airtight polyethylene laminated multilayered sacks
– By using an antioxidant. Amount of antioxidant depends on the degree of
unsaturation of fish meal. The most common commercially used antioxidants
are ethoxyquin (9400-700 ppm) and butylated hydroxyl toluene (BHT)
• Moisture absorption: Controlled by appropiate packaging.

21. Packaging:
Once the meal is ground, it is usually bagged prior to storage. Although bulk
storage is used, provisions must be made to remove heat generated by
chemical oxidation of oil in the meal. If not removed, the meal can get hot
enough to damage the nutritional quality or, in more extreme cases, cause
combustion. If stored in permeable bags, the bags of meal are stacked such
that air can circulate around the bags and remove the excess heat. More
modern systems often use plastic lined bags which are heat sealed. The
plastic is chosen for its oxygen impermeability. Exclusion of oxygen
prevents oxidation and heat generation and limits generation of odours from
the meal.
Storage: In dry, cool and weatherproof condition.

22. CONCLUSION:
• Fish meal is traditionally used as livestock feed supplement,
since it contain higher percentage of protein and essential
amino acids like lysine, methionine and cysteine, which the
animal bodies cannot systhesise.
• It is also a good source of vitamin B complex like
cyanocobalamine(B12), choline, niacin, pantothenic acid and
riboflavin.
• It is rich in minerals like Ca, P, Cu and Fe and also the source of
some trace elements referred as “unknown growth factors”.
• The biological value of fish meal protein is very high.

23. REFERENCES:
• Ninawe A. S, Rathnakumar K, Fish processing technology and
product development in “Fish By-Products and waste utilization”
Narendra Publishing House, Delhi-110006. Pp. no-305-310.
• www.google.com